As the sixteenth licensed limited commercial broadcast station ever licensed by the Radio Division, Bureau of Navigation, Department of Commerce, Preston D. Allen of Oakland, California, was authorized to operate KZM on December 9, 1921. KZM, erected atop the Hotel Oakland, 13th and Harrison, downtown Oakland, was originally permitted to operate on 360 meters (equal to 833 kilocycles) with 200 watts. Limited commercial license number 251 was granted to Mr. Allen's KZM.
On July 21, 1921, an experimental license had been granted by the Radio Division to Mr. Allen, and in October of 1921, a transmitter was installed along with two masts atop the Hotel Oakland. Experimental radiotelephone transmissions were begun in conjunction with the Western Radio School, an enterprise operated by Mr. Allen. Concerts were broadcast every Tuesday and Friday from 8 to 9 p. m. on 325 meters (equal to 920 kilocycles), with news material supplied by the Oakland Tribune newspaper; this liaison led the Tribune to apply for and receive permission to erect its own station, KLX, in May of 1922.
By April of 1922, while licensed to "radio experimenter" P. D. Allen, KZM was "operated by the Western Wireless School." In September of 1922, the tie-in with the Oakland Tribune and the Western Radio Institute was terminated, with Mr. Allen now furnishing all programming for the station. Power was reduced in early 1923 to 50 watts, but in early 1924, was raised to 100 watts. In early 1924, in addition to the operation of his own KZM, Preston D. Allen became Radio Manager of the Tribune's KLX, which was located nearby (in the Tribune Tower at 13th and Franklin Streets). At this time, some programs were shared by both KZM and KLX.
KZM was authorized to change frequency to 1240 kilocycles in early 1925, but in early 1926 switched dial position slightly to 1250 kilocycles. Studio and transmitter remained at the Hotel Oakland, 13th and Harrison Streets. In June of 1927, the newly empowered Federal Radio Commission assigned KZM a new frequency 1220 kilocycles.
On April 1, 1928, KZM underwent several changes which gained FRC approval in March. KZM was then acquired from Mr. Allen by Leon P. Tenney, who moved the station from the Hotel Oakland to a new site in the Palmtag Building, Castro and B Streets, Hayward, California, and changed KZM's frequency to 1300 kilocycles. On the new channel, effective April first, KZM was required to divide time with Berkeley's KRE. Also in April, operation of KZM, now under the ownership of Mr. Tenney, was transferred from the Western Radio Institute to "The Golden West Broadcasting Station," a sales organization headed by Mr. Tenney.
In a nationwide frequency reallocations plan affecting most United States broadcast stations at 3 a. m., Saturday, November 11, 1928, KZM was required to shift its operating frequency to 1370 kilocycles, continuing to share time on the new assignment with KRE at Berkeley. At this time, KZM was located at 880 B Street, Hayward the Palmtag Building while owner Leon P. Tenney resided at 686 38th Street, Hayward. In mid-1929, the operating lease for the commercial hours of KZM was transferred to Federated Broadcasters, which also maintained offices in the Palmtag Building.
On August 8, 1929, KZM temporarily left the air, pending a license renewal hearing with the FRC in Washington. By January 1930, KZM was still reported "silent." In the fall of 1930, KZM's operating lease was transferred by licensee Leon P. Tenney from Federated Broadcasters to the Universal Broadcasting Company. In December 1930, KZM was acquired from Mr. Tenney by Julius Brunton and Sons, operators of a battery and auto service firm and licensee of radio station KJBS at San Francisco.
The Federal Radio Commission announced on March 27, 1931, that the license renewal application of Hayward's KZM was denied, listing assorted charges against the station, including unauthorized ownership change to KJBS Broadcasters (the Brunton group), a history of "frequency wobbling" (not maintaining their assigned carrier frequency), and judging the station "mechanically inferior."
The sale to the Brunton interests was rescinded in March of 1931 after the FRC decision, and on June 23, 1931, KZM formerly assigned 1370 kilocycles (sharing with KRE) with 100 watts was deleted.
Source: Broadcast Pro-File.
The History of KJBS, San Francisco
The History of KNEW, Oakland (not currently online)
The History of KRE, Berkeley (not currently online)
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